【作者】 肖鹏；

【导师】 王进戈；

【作者基本信息】 西华大学 ， 机械电子工程， 2007， 硕士

【摘要】 多杆开链式机器人仅用于有限个相似任务，其灵活性没有得到充分发挥且维护费用较大。另一方面，传统的自动化机构在结构上相对简单，但缺乏灵活性，即使是任务改变得很小，也必须重新设计机构。可调机构是指其某些机构尺寸和/或位置连续调节或手动调节，以实现输出多个任务的机构。它结合了前两者的优点而克服了它们的不足，在生产实践中逐渐获得应用。在自动化生产中，往往要求机器实现几个可供选择的任务，以便机器具有较广的适用性。在这种情况下，可调机构就比机器人有更多的优点，比如可靠性高、精确度好、容易操作和维修、以及能量消耗少等。这些特性使得可调机构具有了广阔的应用前景。本文分别对空间四杆机构和球面五杆机构进行了综合分析研究及对固定平台可调并联机构的运动学和动力学仿真问题进行了系统的研究。提出了可调节型空间RRSS机构刚体导引综合的方法，分杆组分任务独立求解导出了相应综合方程，其中R-R杆组综合时运用了共面和反位移原理，简化了求解的复杂度。通过调节机构部分参数可实现多任务刚体导引综合，给定了任务与最大精确导引位置数之间的关系。运用混沌分形方法求出了综合方程组全部解，并给出了一个数字实例。建立了球面五杆机构的运动学数学模型，根据机构位置正反解分析了机构的各种可能构型，推导出了球面五杆机构的雅可比矩阵，并据此分析讨论了机构的运动奇异性。对球面五杆机构的连杆点进行了位置分析，借助于计算机机构仿真的方法，研究了双曲柄球面五杆机构的连杆曲线随机构参数改变而变化的规律。应用Pro/E软件，建立了固定平台可调2-RPS-2-SPS并联机床的虚拟样机模型，对样机模型进行了运动学、动力学和干涉检查的虚拟仿真，绘出了机构运动学和动力学的变化规律曲线，验证了Pro/E仿真分析的有效性。更多还原

【Abstract】 Mufti-axis open-loop robots are under-utilized and the cost of maintenance is relatively high, when they’re used in limited similar tasks. On the other hand, conventional automation mechanisms are comparatively simpler in structure, but lack in flexibility. Even though the adjustment of the task is very little, the mechanisms have to be redesigned. In adjustable mechanisms, the dimensions and/or the positions of one or several particular links can be adjusted so that the mechanisms can generate different tasks. They have the advantages of above two while overcome their disadvantages.In the automatic production, a machine is required to perform comparatively simple tasks respectively and quickly in case there is intelligence received to select one or the other task. Compared with mufti-purpose robot manipulators with multiple actuators, single purpose, single input purely mechanical devices are more reliable, more accurate, much easier to manufacture and maintain, and more economical. Mechanisms with adjustable links can be used as such devices to perform highly respectively simple sets of tasks. These characteristics make adjustable mechanisms have very vast potential applications. Guidance synthesis, displacement analysis, path synthesis, dynamic analysis of spatial RRSS four-bar, spherical five-bar mechanisms and parallel machine tools are studied in this thesis.A method of rigid-body guidance synthesis for adjustable spatial RRSS mechanism is presented, and the corresponding design equations are derived by divided links and tasks. Particularly, the design equations for R-R link are set by using co-plane and inversion theory. In this way the complication can be simplified. The mechanisms can achieve multiple alternative tasks by adjusting some structure parameters. Then relation between the number of tasks and the maximum number of prescribed precision positions are given. The sets of nonlinear synthesis equations were solved by using chaos optimization algorithm, and a numerical example is given to illustrate it.Based on kinematics model of spherical five-bar mechanism, the analytical solutions of direct kinematics and inverse kinematics are deduced, the working and assembly modes of the mechanism are analyzed, and the mechanism’s Jacobian matrix is derived. The singularity conditions of spherical five-bar mechanism are discussed according to the Jacobian matrix. Then the coupler point kinematics of spherical five-bar mechanism is analyzed. By using the computer simulation method, the coupler curves of spherical five-bar mechanism with double crank and some laws of the curves changing with the mechanism parameters are investigated respectively.Using Pro/E software, the virtual prototype of the 4-Dof 2-RPS-2-SPS Parallel Mechanism with adjustable fixed platform plat is built up and the simulation on the kinematic and dynamic performance is carried out. Curves of the Mechanism’s kinematics and dynamics are acquired. Thus the validity of Pro/E simulation analysis is testified.更多还原